The DCCT is a multicenter cooperative trial in which 21 centers are participating to determine whether normalization of the blood glucose level of Type I (insulin-dependent) patients can prevent the complications of retinopathy, nephropathy and cardiovascular disease. Two of the four phases of the study have been completed: Phase I, the protocol was designed; Phase II, patients were recruited, randomized and observed for feasibility and safety of normoglycemia. The NYH-CUMC recruited 15 patients in Phase II although only 12 were required. Since the clinics were notified to begin recruitment for Phase III, the New York Hospital-Cornell University Medical Center has randomized five patients and, thus, are ahead of the recommended December deadline. No difficulty is anticipated in meeting future recruitment goals. The greater New York- Metropolitan area has a population of approximately 13,000,000, which includes many individuals with Type I diabetes. The New York Hospital-Cornell University Medical Center is a large teaching hospital complex which enjoys a superb reputation in the surrounding community. The Clinic is geographically ideally situated in mid-town Manhattan and is readily accessible by public transportation; therefore, it is in an excellent environment for accomplishing the goals of the study.